In recording and stimulating neurons either in the peripheral or central nervous system, electrophysiological methods (e.g., neural probes, patch clamp measurements, etc.) are the gold standard. However, these methods are limited in spatial and temporal characteristics. For instance, some probes are large (e.g., on a millimeter scale) and, therefore, lack spatial precision in either stimulating or detecting individual neurons or isolated regions within neural tissue. In another instance, some probes can be difficult to implant and maintain without complications and degradation both in the target tissue and within the biological system. Accordingly, new probes and apparatuses having such spatio-temporal control are desired. In particular, systems employing such probes would be beneficial for biological links between the nervous system and an external unit (e.g., a prosthetic for an amputated limb).
Furthermore, current developments in optogenetics have opened up the possibility of studying neurons and neuronal networks in vivo. In optogenetics, light sensitive ion channels or other molecules are expressed in transfected, genetically engineered cells, such that directed optical signals can be used to selectively activate or stimulate these engineered cells. Thus, new tools and methods to enable in vivo studies while minimizing invasive procedures would be beneficial.